Mum isn't in .She has _to Hangzhou on business

问题描述:

Mum isn't in .She has _to Hangzhou on business
a,gone b,been并说明理由
但老师说选b

Mum isn't in .She has to Hangzhou on business
has gone to 表示去了某地,现在还没回来
has been to 表示去过某地,现在也已经回来了
(尽量用简洁的语言表述给你,)